Being a dissident in Vietnam has always been a dangerous business, and it’s getting more so. Ranked as the world’s 8th worst country for online freedom in 2012 by Freedom House, Vietnam has seen over 50 bloggers and activists arrested already this year, according to Human Rights Watch (HRW).

Things got even tighter for the country’s 30 million Web users when the government began enforcing the now infamous Decree 72 on Sept. 1. Among other things, the vaguely worded law bans the publishing of material that “opposes” the Socialist Republic of Vietnam or “harms national security.” Definitions of offending matter are disconcertingly broad and could, for example, include news, which would make it illegal for Vietnam’s 16 million Facebook users to discuss articles, or even to post links to them. A ban on messaging platforms such as WhatsApp, Viber and Line has also been proposed.

“Decree 72 will be all about selective enforcement, going after people the government has decided it doesn’t like and nailing them for sharing news through social media,” says Phil Robertson, deputy Asia director for HRW. But bloggers and activists are not giving into the government’s ever growing determination to silence free speech. Instead, they’re getting smarter about the ways in which they put their messages across. Step forward Viet Tan, a pro-democracy group using its Washington, D.C.–based office to offer online lessons in evading cybersurveillance.

Since 2009, Viet Tan has trained hundreds of online activists over Skype, or sometimes in person. Bloggers are taught how to communicate securely by encrypting messages and files, how to wipe incriminating data from their computers and how to conceal IP addresses through a range of techniques. The group has even launched nofirewall.blogspot.com, a sort of Anarchist’s Cookbook for online activists, featuring a host of useful tips (although how to hack government sites isn’t among them — Viet Tan has a nonviolent ethos).

The group also hopes to educate ordinary Vietnamese in cybersafety. It has produced a music video parody of Justin Timberlake’s “Sexy Back,” which shows viewers how to “bring Facebook back” from behind a firewall, and issued a cartoon take on Romeo and Juliet, which highlights the dangers of phishing and using unsecured browsers.

Unsurprisingly, Hanoi regards Viet Tan as a subversive organization. In January, 14 activists were sentenced to lengthy prison terms after attending a Viet Tan training session in Bangkok, with authorities alleging that participation amounted to an “attempt to overthrow the government.”

“The Communist Party controls everything and can arrest anyone who criticizes,” says Nguyen Van Dai, a prominent blogger and lawyer who has been trained by Viet Tan. Dai was jailed for four years in 2007 for lecturing students on human rights and remains under house arrest until 2015. “The security agency sends officers to threaten the families of bloggers and democratic activists. They also pressure their employers, so most dissidents lose their jobs.”

However, such repression only increases the resolve of many online activists. “With all media outlets controlled by the state in Vietnam, bloggers are the de facto media,” said Viet Tan spokesperson Hoang Tu Duy. “The regime wants to squelch freedom of expression and has a litany of repressive techniques, but they will fail because of the sheer will of Vietnamese to have a voice and utilize modern technology.” To Duy, circumventing Internet restrictions “is the civil disobedience of the 21st century.”

Though the government attempts to restrict technology (delaying, for example, the rollout of 4G mobile networks), smartphone usage is also soaring, with Vietnam the second fastest growing market in the world. Like their counterparts in other countries, Vietnamese activists have made prolific use of smartphones to share photos and make microblog posts. To help them, Viet Tan has launched several apps providing news, training tips and access to the Tor network — a free proxy that ensures Web traffic from mobile phones cannot be traced.

Despite the government’s beefed-up legal powers, funding for large-scale digital surveillance is scarce in this still developing country. When it comes to the blogosphere and social media, the bulk of filtering is delegated to Internet Service Providers (ISPs). However, Masashi Crete-Nishihata, research manager at the Citizen Lab, a Toronto-based technology watchdog, found in a recent study that although Vietnam restricts access to websites through a range of methods, success varies greatly depending on which ISP is used.

Dissidents remain hopeful that the international community will condemn Hanoi’s escalating surveillance culture and call for change — especially now that Vietnam is in the middle of negotiations over lucrative trade deals with the E.U. and the U.S. But they could be in for a long wait. “Hanoi is counting on the complacency of Vietnam’s international donors who continue to say little about this crackdown,” says Robertson.